Hydraulic cylinders with internal piston and output shaft are commonly used to effect linear movement of an item that is connected to the output shaft. Although ruggedly built to withstand the task at hand, some cylinders may be subjected to such extraordinary repetition and/or pressure spikes that failure of the piston or rod (i.e. fracture) or failure of the connection between them can occur. In one example, vehicles configured for hauling heavy loads (e.g. 30 tons or more) may employ long (e.g. 60 or 80 inches or more) cylinders that may both move the load onto and off the vehicle, and hold it in place during transport. Sudden acceleration or deceleration of the load or shaking thereof can be transmitted through the output shaft to the internal piston. Because the cylinder is in an idle state and its input/output valves are closed, the hydraulic fluid has nowhere to go, and the enormous pressure spike can and often does cause the aforementioned failure.
Improvements in such hydraulic cylinders to better resist, if not all but eliminate such failures is desired.